NB/T 47019.3-2021 Technical conditions for ordering tubes for boilers and heat exchangers Part 3: Non-alloy steel and alloy steel specifying high-temperature properties (English Version)
2021NB/T 47019.3-2021 Technical conditions for ordering tubes for boilers and heat exchangers Part 3: Non-alloy steel and alloy steel specifying high-temperature properties
2011NB/T 47019.3-2011 Purchase technical specification for boiler&heater exchanger tubes/pipes.Part 3:Non-alloy and alloy steel with specified elevated temperature properties